Answer:
<em>vf=79.38 m/s</em>
<em>y= 321.5 m</em>
Explanation:
<u>Free Fall Motion</u>
A free-falling object falls under the exclusive influence of gravity. Free-falling objects do not encounter air resistance.
If an object is dropped from rest in a free-falling motion, it falls with a constant acceleration called the acceleration of gravity, which value is .
The final velocity of a free-falling object after a time t is given by:
vf=g.t
The distance traveled by a dropped object is:
1.
The penny will fall for t=8.1 s before hitting the ground, thus the height from which it was dropped is:
y= 321.5 m
2.
The final velocity is:
vf=79.38 m/s
Speed = distance / time
Velocity = displacement / time
So ,
Speed = 50 km / 0.5 hr = 100 km/h
Velocity = 40 km / 0.5hr = 80 km/h